Expression of angiogenic growth factors in laryngeal carcinoma
Korampalli, Tirupati Srinivasu
Thesis or dissertation
- © 2012 Tirupati Srinivasu Korampalli. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.
Head and Neck cancer is the sixth most common malignancy in the world and each year over 2,200 cases of carcinoma of the larynx are diagnosed in the UK. Patients have an overall five-year survival rate of 67%. Despite advances in treatment, patient prognosis is poor largely due to recurrence. The formation of new blood vessels (angiogenesis) is vital for the growth and metastasis of solid tumours, with the expression of key angiogenesis-related proteins having been shown to have prognostic significance. This study aims to identify key proteins within the tumour microenvironment, which may be involved in angiogenic processes occurring in laryngeal carcinoma, and associated metastatic nodes at different stages of disease, and to evaluate any potential therapeutic value.
Both laryngeal tumour tissue and associated metastatic nodes were obtained from seven patients undergoing surgical resection; control uvula tissue was obtained from five healthy volunteers undergoing uvulopalatopharyngoplasty. Protein was extracted from the tissue using a commercial kit (Proteojet lysis reagent, Fermentas Life Sciences, York, UK, Calbiochem/Merck, Nottingham, UK) and the expression of 55 angiogenesis-related proteins was determined using a human angiogenesis array (R&D systems). Subsequently the level of six of the 55 angiogenesis-related proteins showing the greatest level of difference were determined in the tissue lysates using ELISA (R&D Systems) in a cohort of thirty six patients diagnosed with laryngeal cancer. The patient group comprised 30 men and 6 women with a mean age of 68 years (range 51-89).
The relative expression of 32/55 angiogenic-related proteins increased in tumour tissue between stage T1 to T3-T4 and the same trend was seen for 29 of these proteins in nodal tissue; MMP9, platelet factor 4 and Serpin E1 did not show an increase until T4. Thirty-one of the 32 proteins were expressed at a higher level in T3/T4 tumour tissue compared with the corresponding node, and 29/32 proteins were expressed more highly in T1 tumour compared with T1 node. The level of expression of these 27 proteins was consistently higher in T4 tumour tissue compared with control.
Specific analysis of the six most differentially expressed angiogenic-related proteins demonstrated increased levels of angiogenin in early stage tumours (p =0.034) compared with late stage of the tumour and increased IGF BP3 in tumours compared with the matched metastatic nodes (p = 0.016). No statistically significant results were observed for VEGF, FGF, TIMP1 or IL-8.
Survival analyses revealed that none of the factors were associated with recurrence or patient’s survival.
In summary this study suggests that a network of proteins present in the tumour microenvironment are likely to be involved in angiogenesis and therefore contribute to growth and metastasis of laryngeal tumours during the later stages of tumour development. Angiogenin and IGF BP3 may play a role in tumour progression of laryngeal malignancies, although they demonstrated no significant role in predicting the survival of the patients with laryngeal malignant tumours.
- Postgraduate Medical Institute, The University of Hull
- Stafford, Nicholas; Greenman, John (Professor of tumour immunology)
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